Your daily sending volume is limited, depending on your inbox provider. Indeed, exceed the limits set by providers could result in negative consequences for your inbox (drop in email deliverability, account blocking, etc.)
The maximum amount of emails sent per day from your inbox also depend on your Warmbox plan.
At any time, you can consult your sending limits and/or upgrade your plan in order to increase your daily sending volume and add more inboxes.
1. Open the "Settings" tab
2. In "Billing" section, select the "Subscriptions" tab and consult your sending limits